An aerial vehicle, such as a missile, tends to be sped up to reach a target point in a short period of time. In addition, a flying range of the aerial vehicle tends to be increased in order to be able to reach a target point farther away. Moreover, the aerial vehicle tends to be exposed to an environment of high aerodynamic heating as the speed of the aerial vehicle increases or the flying range of the aerial vehicle increases.
In order to adapt to the environment of high aerodynamic heating, a technology using heat resisting alloy for surfaces of the aerial vehicle 1 is known (FIG. 1). Note that the heat resisting alloy generally has high density. Therefore, in case of using the heat resisting alloy for the surfaces of the aerial vehicle, its weight becomes heavier.
Alternatively, a technology using ablation material for the surfaces of the aerial vehicle 1 is known (FIG. 2). Thereby, heat input from the environment to the aerial vehicle 1 is reduced as a result of melt of the ablation material. Note that a shape of the ablation material is changed as the ablation material disappears (as the ablation material wears, melts, etc.). Therefore, aerodynamic characteristics of the aerial vehicle changes as the shape of the ablation material changes when the ablation material is used as material of outer surfaces of the aerial vehicle.
JPH4-306500A discloses an aerial vehicle having a switching device which changes a value of control gain before a main propulsion device starts operation to another value of the control gain after the main propulsion device starts operation. However, a surface material of the aerial vehicle that is described in JPH4-306500A is unclear.